The girl, whose name has not been released, told police she was kidnapped by the man who had stopped her on the street on her way home from school, according to public broadcaster NHK and other media.

He enticed her into his car by saying her parents were divorcing, and forced her to write the note to them.

The 23-year-old man, identified as Kabu Terauchi, graduated from Chiba University east of Tokyo this month, having apparently attended school for two years while holding the girl in his apartment, the reports said.

After he graduated the pair moved to a Tokyo apartment. On Sunday she took advantage of his absence to escape.